The invention relates to a reciprocating-pistontype internal combustion engine, in particular for the operation of passenger automobiles, wherein the cylinder head and the upper portion of the crankcase are integrally casted and the connecting-rod bearings on the crankshaft are supplied with lubrication oil via ducts provided in the crankshaft.
Engines for passenger automobiles are generally operated on a very low percentage of the rated power, particularly in urban areas, on roads or in column traffic. In conjunction with the internal losses of the necessary auxiliary units and such accessories as serve for the increase of comfort, the internal losses of the engine are about the size of this average actual output. Therefore, such measures as tend to avoid loss of power on the engine may be expected to lead to correspondingly high fuel savings. Further fuel economies may result from a reduction of the weight of the engine and from reduced dimensions of the engine.